get a support signoff. Also the corosync updates have not finished
through our validation process. Only hot fixes (from support) are
available
Regards
-steve

Sorry to re-open this thread ... But exists any news about this problem??

In fact, there is !
It appears that this situation is within the microcode of some specific
xeon "nahalem" (sorry for the spelling) processors... It has to do with
switching cstate and the way rhel6.1 now switch state that was not done
in 6.0.
You can look at bugzilla # 710265 and kb docs # 61105.
Our temporary fix for the moment was to disable cstate transition by
adding :
intel_idle.max_cstate=0 processor.max_cstate=1
to the kernel line in grub.conf, update and reboot. We hadn't had any
cpu spikes on any of the 5 nodes we've updated yet. The 3 remaining
still haven't been updated due to production downtime.
Get a support signoff for this, I'm in no way endorsing this solution,
as I can't know if you're in the same situation as mine.